Cannot download www.hp.com/ePrint/DJ2540 onto my iPad 3 or iPhone 5s

So I have an iPad3 and an iphone 5s and today purchased this printer so I am meant to go to www.hp.com/eprint/DJ2540 and follow the link to download. But it doesnt work. It is just constantly saying there was an error downloading, come back later or use the disk. I cannot see any other way to download the software I need. Does anyone have any ideas how I can get this to work?
With thanks
David